fix(core): update

2022-05-30 23:15:32 +02:00
parent 57edbb872b
commit 5b6436b023
7 changed files with 169 additions and 8 deletions
--- a/ts_web/elements/dees-pdf.ts
+++ b/ts_web/elements/dees-pdf.ts
@@ -0,0 +1,120 @@
+import { DeesElement, property, html, customElement, domtools } from '@designestate/dees-element';
+import { TemplateResult } from 'lit-html';
+
+import { Deferred } from '@pushrocks/smartpromise';
+
+import type pdfjsTypes from 'pdfjs-dist';
+
+declare global {
+  interface HTMLElementTagNameMap {
+    'dees-pdf': DeesPdf;
+  }
+}
+
+@customElement('dees-pdf')
+export class DeesPdf extends DeesElement {
+  // DEMO
+  public static demo = () => html` <dees-pdf></dees-pdf> `;
+
+  // INSTANCE
+
+  @property()
+  public pdfUrl: string =
+    'https://raw.githubusercontent.com/mozilla/pdf.js/ba2edeae/examples/learning/helloworld.pdf';
+
+  constructor() {
+    super();
+
+    // you have access to all kinds of things through this.
+    // this.setAttribute('gotIt','true');
+  }
+
+  public render(): TemplateResult {
+    return html`
+      <style>
+        :host {
+          font-family: 'Roboto', sans-serif;
+          display: block;
+          box-sizing: border-box;
+          max-width: 800px;
+        }
+        :host([hidden]) {
+          display: none;
+        }
+
+        #pdfcanvas {
+          box-shadow: 0px 0px 5px #ccc;
+          width: 100%;
+        }
+      </style>
+      <canvas id="pdfcanvas" .height=${0} .width=${0}></canvas>
+    `;
+  }
+
+  public static pdfJsReady: Promise<any>;
+  public static pdfjsLib: typeof pdfjsTypes;
+  public async connectedCallback() {
+    super.connectedCallback();
+    if (!DeesPdf.pdfJsReady) {
+      const pdfJsReadyDeferred = domtools.plugins.smartpromise.defer();
+      DeesPdf.pdfJsReady = pdfJsReadyDeferred.promise;
+      const loadDeferred = domtools.plugins.smartpromise.defer();
+      const script = document.createElement('script');
+      script.addEventListener('load', () => {
+        console.log('pdf.js loaded!');
+        loadDeferred.resolve();
+      });
+      script.src = 'https:////mozilla.github.io/pdf.js/build/pdf.js';
+      document.getElementsByTagName('head')[0].appendChild(script);
+      // The workerSrc property shall be specified.
+      await loadDeferred.promise;
+      DeesPdf.pdfjsLib = window['pdfjs-dist/build/pdf'];
+      DeesPdf.pdfjsLib.GlobalWorkerOptions.workerSrc = '//mozilla.github.io/pdf.js/build/pdf.worker.js';
+      pdfJsReadyDeferred.resolve();
+    }
+    await DeesPdf.pdfJsReady;
+    this.displayContent();
+  }
+
+  public async displayContent() {
+    await DeesPdf.pdfJsReady;
+
+    // Asynchronous download of PDF
+    const loadingTask = DeesPdf.pdfjsLib.getDocument(this.pdfUrl);
+    loadingTask.promise.then(
+      (pdf) => {
+        console.log('PDF loaded');
+
+        // Fetch the first page
+        const pageNumber = 1;
+        pdf.getPage(pageNumber).then((page) => {
+          console.log('Page loaded');
+
+          const scale = 10;
+          const viewport = page.getViewport({ scale: scale });
+
+          // Prepare canvas using PDF page dimensions
+          const canvas: any = this.shadowRoot.querySelector('#pdfcanvas');
+          const context = canvas.getContext('2d');
+          canvas.height = viewport.height;
+          canvas.width = viewport.width;
+
+          // Render PDF page into canvas context
+          const renderContext = {
+            canvasContext: context,
+            viewport: viewport,
+          };
+
+          const renderTask = page.render(renderContext);
+          renderTask.promise.then(function () {
+            console.log('Page rendered');
+          });
+        });
+      },
+      (reason) => {
+        // PDF loading error
+        console.error(reason);
+      }
+    );
+  }
+}